Showing posts from February, 2005

Standard & Non-standard DNA, RNA, and Protein Alphabets

In bioinformatics/computational biology, a sequence is represented by ordered succession of characters (1-letter code of DNA/RNA/amino acid) known as alphabets. The standard type of alphabets include DNA alphabet [A, T, C, G], RNA alphabet [A, U, C, G], and amino acid alphabet [A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, Y]. While, non-standard alphabets include DNA/RNA alphabet [B, D, H, K, M, N, R, S, V, W, Y], and amino acid alphabet [B, J, O, U , X, Z]. List of standard and non-standard DNA/RNA alphabets with 1-letter code is given in table below. Nucleotide 1-letter code Adenine A C, G, T B Cytosine C A, G, T D Guanine G A, C, T H G, T K A, C M A, T, U, C, G N A, G R G, C S Thymine T Uracil U A, C, G V A, T W C, T Y List of standard and non-standard amino-acid alphabets with 3-letter code